Hydroplane



June 10, 1930. G. B. HOOTON 1,762,626

HYDROPLANE Filed Jan. 25, 1928 2 Sheets-Sheet 1 IN VEN TOR 501 1012 5. //00/'0/7 BY 6 M ATTORNEY June 10, 1930.

G. 5. HOOTON HYDROPLANE 2 Sheets-Sheet 2 Filed Jan. 23, 1928 Patented June 10, 1930 PATENT OFFIE GORDON B. HOOTON, 0F GRAND RAPIDS, MICHIGAN- HYDROPLANE Application filed January 23, 1928.

The main objects of this invention are:

First, to provide a hydroplane which is very light and rigid in construction.

' Second, to provide improved means to induce banking of the hydroplane thereby reducing the chance of an accident.

Third, to provide a means whereby the directional ability of the boat is not hampered while it is skimming over rough water at a high speed.

Fourth, to provide a means whereby the boat can make turns at a high speed permitting suflicient skidding yet not needlessly retarding the speed of the boat by high pressure area of water under the outside edge of the boat.

Further objects and objects pertaining to details and economies will definitely appear from the description to follow.

I accomplish the objects of my invention bythe devices and means described in the following specification. The invention is clearly defined and pointed out in the claims. 1

A boat embodying my invention is clearly illustrated in the accompanying drawing forming a part of this specification, in which:

Fig. l is a side elevation of my improved hydroplane. r

Fig. 2 is a cross section on line 2-2 of Fig. 1 showing detail of the fin construction.

Fig. 3 is a cross section on line 33 of Fig. 1 showing a construction of the hull.

Fig. 4: is a detail Vertical sectional elevation, on line l-sl. of Fig. 2-, of the skid resisting hydro-fin and its mountings, the fin itself and adjusting means being shown in full lines.

Fig. 5 is a cross section conventionally illustrated of a modification of the hull showing the fiat central portion and the curved side portions thereof.

Fig. 6 is a cross section conventionally illustrated of a modification, curved in the center and straight at the sides.

Fig. 7 is another cross section of a modification, straight in the center and sides.

Fig. 8 is a longitudinal detail sectional Serial No. 248,814.

view through the hull showing a modified form of the fin.

Fig. 9 is a longitudinal section on line 9-9 of Fig. 7, the dotted lines show the movement or flexing of the fin.

In the drawing the parts will be identified by their numerals of reference which are the same in all the views.

1 is my improved hydroplane. 2 is the side thereof. true circle. at is a step in the bottom forming the offset bottom portion 41.

5 is the flexible fin located centrally of the hull and forward of the center of gravity. 51 is an upwardly projecting shank cast integral with the fin. 52 is the upright bearing member secured to the bottom by its flange. 53 is a square end of the shank. 54 is a handle mounted thereon slotted at 55.

6 is an adjustable flexible spring engaging the slot. 61 is a pivot support for the same. 62 is the thumb screw for securely clamping the flexible spring when adjusted.

By adjusting the flexible spring 6 in the slot the tension on the fin is thereby decreased or increased. As the flexible spring is moved toward the fulcrum of the lever the leverage is shortened thereby making the fin more flexible, and as it is moved outward from the fulcrum the stiffness of the fin is increased.

In the modification the fin 7 is mounted on the hinged member 71 secured to the hull bottom of the boat. A flattened portion 72 on the hinge member and 73 on the fin are separated and provides with a cushioning member 74 formed of rubber or the like to provide a sufficient yielding or flexing of the fin.

In the modification of the hull shown in Fig. 5 it is constructed with a central flat portion 8 and curved portions 81.

In Fig. 6 the hull has a curved portion I 9 and flat portions 91.

In Fig. 7 the hull is constructed of the central fiat portion 10 and flat side portions 101.

In a light hydroplane for outboard motors, the outboard motor is carried high,

3 is the bottom curved on a R and sometimes weighs more than the hull itself, so that the center of gravity of the outfit is too high for safety in a sharp turn unless provision is made in the design of hull to induce self-banking toward the inside of turn. The hulls are necessarily very flat, to promote. the skimming over the surface which makes for speed. Thus they have very little directional ability. You can turn them almost directly crosswise to the direction of travel when planing along at full speed and they will skid along sidewise and not go where pointed.

Hence it is common practice to mount a small metal fin or centerboard somewhere along the bottom. If this fin is near the after portions of the hull, about under the center of gravity, it has the duty of holding the entire weight of the outfit from skidding on the turns. If it is large enough to actually do this, it is too large to permit maximum speed on the straightaway. If it is smaller, so that it skids a little, it banks up a high pressure area of water under the outside edge of the hull, lifting the hull till water is released, then allowing it to drop, repeating the action. This produces a sort of cornerwise galloping action which is undesirable and dangerous. However, this installation is common to many of the best makes of racing boat. I

If the fin is placed pretty well forward, it does not have so much load to hold, and its banked-up water does not lift the hull sufficiently to cause gallop. However, on a short boat the distance between the fin and the steering gearis necessarily'so short that a slight deflection of the motor puts the boat into quite a sudden turn, like a short wheelbase car. If the fin is large enough to hold onto the water, even though it is well forward, the turn is sharp enough to exert quite a side pressure on both fin and underwater parts of motor, each having a tendency to hold the boat from skidding to the outside. These pressures are centered so far below the center of gravity that there is a strong overturning moment, and tae boat tends to bank toward the outside of the turn, which is dangerous and uncomfortable.

This is the reason, chiefly, for the curved shape of the hull cross section. I aim to set up an inwardbanking moment of the hull, to overcome the outward tipping moment of a low fin and a high center of gravity. My boat is necessarily skidding some to the outside since the motor is turned slightly that way, permitting the stern to slide some. By adopting a broad V or convex curve across the bottom of the hail, this skidding causes the outside portions of the bottom to hit the onrushing water with a greater angle of incidence than the inside portions, thus exerting greater dynamic lift yeaeae under the outer edge of the hull, and losing some of the lift under the inner edge. Au inward banking tendency is the result.

If the broad V is used, as in common practice, it must be kept very flat, or the boat will not act right on the straightaway. It will ride up on the ridgeof the v and fall to either. side and stay there. And if it is kept flat enough to act right on the straightaway, it is toofiat to have enough banking effect for entire safety "on sharp turns. Thus afairly flat center section is necessary to give the boat a natural stability when running straight. The. center of the curve of the bottom should be above the center of gravity. Yet the bottom must curve up near the edges to exert the desired banking moment on turns. A smooth broad curve is found in practice to be satisfactory, although a complex cross section made of a series of curves and straights, and-even a series of straights, not joined by curves, can be used to good advantage; The smooth curve is the preferred form, as it creates less eddy resistance during skidding. It ismy belief that any of these forms which show. a fairly flat center section and upturned edges, is unique as applied to a step hydroplane.

A further advantage of the curved cross section is that it gives us quite a steep angle, way out near the edge, where the leverage on the hull is greatest; Thus a strong bankingmonient can be had with. only a small amount of side skid; This is necessary to combat the very strong overturning moment of the fin. A further benefit is that it keeps the chines, or edges of the bottom, clear of the water at high speed, so that small waves do not lap against the sides of the boat so easily. These waves are especially bothersome when running across the sea, or diagonally into it. They cause deflections of the direction if they hit the curved-in forward sides, thus causing sudden tipping tendencies. The broad square bow, like a scow, used on my hulls, combines with the high riding chines, to eliminate this trouble. A further, and important advantage of the curved underbody is that it permits the boat to ride along on a fairly narrow strip of planing area. A fiat. bottom could not do this, and a V bottom would not layright.

Tests show that even with a maiimum practical curvature in the boat bottom, a short boat will pull around the turn too quickly to permit the self-banking moment of hull to overcome the tip-over tendency of fin and motor; So I make a small fin to permit some skidding. This reduces the fin loads, and the added skid increases the self-banking moment. We find that the smaller fin feels about right for a while, then unexpectedly lets go of thewater when air chances to get behind it, and we go into a wild skid. I remedy this by use of a fin large enough to hold onto the water, but mount it flexibly so that it yields just enough to give the amount of skid desired. A flexible blade, a hinged blade with elastic centering means, or a rudder-like blade mounted. on a stock which extends inside the hull, and is held flexibly centered by adjustable spring means, are among the devices I use for this purpose. This fin is mounted forward of the center of gravity, so it will share its work witn the motor in pulling the boat around the turn, and thus not have to be so large as to materially reduce the straight-- away speed. The motor is in the water anyhow, so it might as well work to hold the boat in a turn, and. save fin area.

The flexible fin takes the kick out of minor deviations, and permits of quite careless handling of the tiller within reasonable limits. The tension does not commence to be felt on the fin until it has deflected away from neutral a short distance. These little deviations do not deflect it far enough to put much stress on it, and hence the effect is very mild and. not dangerous. But when one puts the tiller over to go into a turn in earnest, the fin yields enough to take some tension, and then holds just right.

Another advantage with this fin is that on a turn in rough water, where the bow is in and out alternately, a rigid fin pulls the boat around the turn in a series of severe jerks, each one tending to tip a boat over. he flexible fin can be larger, is in contact with the water a greater percentage of the tune, and yields when the jerks come, smoothing out the turning action.

Having thus described my invention what I claim as new and desire to secure by Let.- ters Patent is:

1. In a hydroplane for outboard motors the combination of the body having a fiat se w shaped bow and stepped bottom each section of which is in the form of a segment of a cylinder with the outer sides upwardly deflected and forming an angular corner ateach edge, a fin centrally disposed forward of the center of gravity with upwardly sloping forward end, a pivotal support therefor (aimpr sing an upwardly extending stock d in an u iright bearing, a longirmnally slotted lever connected to the said stock, a pivotally adjustable blade spring to act in the said slot with means for adjusting the same, as specified.

2. In a hydroplane the combination of the body having stepped bottom each section of which in the form of a segment of a cyl inder with the outer sides upwardly deflected and forming an angular corner at each edge, a fin centrally disposed forward of the center of gravity with upwardly sloping forward end, a pivotal support therefor comprising an upwardly extending stock supported in an uprightbearing, a longitudinally slotted lever connected to the said stock, a pivotally adjustable blade spring to act in the said slot with means for adjusting the same, as specified.

3. In a hydroplane the combination of the body having a stepped bottom each section of which is in the form of a segment of a cylinder with the outer sides upwardly deflected and forming an angular corner at each edge, a fin centrally disposed forward ofthe ce ter of gravity with upwardly sloping forward end, and a yielding spring support therefor, as specified.

at. In a hydroplane the combination of the body having a stepped bottom, a fin centrally disposed forward of the center of gravity with upwardly sloping forward end. and a yielding spring support therefor, as specified.

5. In a hydroplane the combination of the body having a fiat scow shaped bow, straight sides and stepped. bottom each section of which is in the form of a segment of a cylinder with the outer sides upwardly defiected, a fin on the bottom centrally disposed forward of the center of gravity with upwardly sloping forward end, and a yielding spring support therefor, as specified.

6. In a hydroplane the combination of the body having straight sides and stepped bottom each section of which is in the form of a segment of a cylinder with the outer sides upwardly deflected, a fin on the bottom centrally disposed forward of the center of gravity with upwardly sloping forward end, and a yielding spring support therefor, as specified.

7. In a hydroplane the combination of the body having straight sides and stepped bottom each section of which. is in the form of a segment of a cylinder with the outer sides upwardly deflected, a fin on the bottom centrally disposed forward of the center of gravity, and a yielding spring support therefor, as specified.

8. Inahydroplane for outboard motor use the combination of the body having straight sides and stepped bottom each section of which is in the form of a segment of a cylinder with the outer sides upwardly deflected, a flexibly mounted fin on the bottom centrally disposed, forward of the center of gravity and with otherwise clear unobstructed bottom surface.

9. In a boat of the planing type for outboard motor use, a skid-resisting hydro fin which is flexibly mounted so as to yieldingly resist skidding of the boat on a turn and disposed forward of the center of gravity.

10. In a boat of the planning type for outboard motor use, the combination of a bottom which is convexly curved in cross section, with a flexibly mounted skid-resisting fin disposed forward of the center of gravity and with otherwise clear unobstructed bottom surface.

11. In a boat of the planing type, the combination of a bottom which is convexly curved in cross section, with flexibly mounted skid resisting fin.

12. In a boat of the planing type, the combination of abottom which is convexly curved in cross section, with a flexibly mounted adjustible tension fin.

13. In a boat of the step hydroplane type,

a bottom with contacting surface which 1s convexly curved in cross section with smooth broadly curved surface, the edge of the floottom meeting the sides and forming there a non-rounded corner, and a flexibly mounted skid-resisting hydro-fin mounted and disposed forward of the center of gravity.

In Witness whereof I have hereunto set myhand.

GORDON B. HOOTON. 

